TTCN-3 has been extended several times since its initial definition. Some of the extensions are clearly separated from the core language and have been defined in new parts of the standard. Examples of such extensions are the IDL to TTCN-3 mapping  and the documentation comments . Other extensions are closely related to already existing concepts of the core language and have been included in the definition of the TTCN-3 core notation. The definition of template variables and the definition of alive test components are examples of such extensions. Lately, TTCN-3 has been extended by several new concepts, such as behaviour types and support for real-time testing. These concepts have been defined in separate extension packages to keep the core notation stable and to avoid the situation where all TTCN-3 users would have to care about them, even when not needing them.
Each extension package defines the new concepts as additions to the core notation. But it also provides the corresponding additions to other parts of the standards: Corresponding to the definition of the concepts in the core notation their semantics have to be defined in the operational semantics. In most cases, the extensions also require additions to the TRI TTCN-3 Runtime Interface and TCI TTCN-3 Control Interface, for example by defining the corresponding logging operations for the newly defined concepts. As such, each extension package is a self-contained document, extending several ...